System and method for disabling RFID tags

ABSTRACT

The invention provides protection to wireless portable transponders from unauthorized interrogation by employing a mechanical means for disabling reception by or from the antenna of the transponder. Transponders include RFID tags that are attached to items that a persons may purchase or carry. Such transponders generally have means for receiving and storing electronic and other information, commonly in binary form using memories as in electronic circuits, etc. The invention is designed to provide privacy of electronic information. The tags can be protected from receiving or providing unauthorized or unwanted information. The invention provides the mechanical means that permit the owner to decide when reception/interrogation of personal or other information is not desired by employing the provided mechanical disable control means.

This application is a continuation of U.S. patent application Ser. No.10/946,975 (now U.S. Pat. No. 7,277,016) Sep. 22, 2004 to which priorityis claimed and which is incorporated herein by reference in itsentirety.

FIELD OF THE INVENTION

The present invention is related to providing wireless portabletransponders, such as cards and RFID tags, with user controlled meansfor disabling the tags as protection from an unauthorized interrogation.More particularly, the invention provides mechanical means that permit auser to decide to disable a tag and observe that the tag has beeneffectively disabled when transponder reception/interrogation ofpersonal or other information is undesirable.

BACKGROUND OF THE INVENTION

Portable transponders, employ RFID, Radio Frequency Identification, asthe technology used to collect highway tolls, to serve as personalidentification for access control, and to provide means for electronicinformation interchange, such as credit, etc. Passive RFID tags (i.e.tags without internal power sources such as batteries) and wirelesscards contain chips, (also known as computer chips, microchips, memorychips) which store identification and other information, such as creditcard numbers, financial data, etc. Tags may be applied to items toidentify the item in much the same way that bar codes are used foridentification purposes. Information is retrieved from a tag as well asthe wireless cards of the present invention by an RFID base station orreader when the tag or card is scanned with radio waves by the reader.The tags may draw their power to function from the interrogation fieldsupplied by the base (read/write) station.

Passive tags are described in U.S. Pat. No. 3,713,148, Card Apparatusand System, issued to Cardullo and Parks. In its simplest form the RFIDtag or device includes a circuit, typically a silicon chip, althoughmore than one chip may be used in the construction of the RFID device.

The circuit is generally connected to an antenna. The RFID device orcard may take on a variety of forms including that of a tag, a key fob,or a card. As previously mentioned, a battery may also be employed toextend the range of the device. It is also possible in principle tobuild devices that function as tags or wireless cards using electricalcircuits including only resistors, capacitors and inductors as is wellknown by those skilled in the art.

Large scale retailers and their suppliers are pursuing Radio FrequencyIdentification, RFID, tagging for supply chain tracking of goods.Demonstrations of RFID for item tagging will lead to point of sale checkout and data collection. For the item tagging application, RFID tags areattached to some part of an item that is being inventoried or is forsale. The attachment may be such that the tag is not visible since thetag may be placed within a container section of the item or packagingmaterial of the item. Removal of the tag after it is no longer usefulcan become difficult if not impossible for many practical situations.Thus, the tag will in many cases remain attached to the item that hasbeen sold to a customer. This makes it possible for the tag to be readafter the point of sale. This in turn leads to a question of the privacyof the purchaser or customer. The issue of privacy is of utmost concern.It is therefore desirable under some circumstances to deactivate ordisable the RFID tag after the point of sale without having tophysically remove the tag. Deactivation of the tag is one way to assureprivacy.

Temporary deactivation of tags may not satisfy privacy concerns. RFIDprotocol proposals 9 include a kill command that renders the taginoperable. This kill command is often referred to as a “Privacy”command—which can be used to permanently deactivate the device at theend of its working life, for example as a customer leaves a store.However, there are two problems associated with the kill command. First,the execution of a kill command is only protected by a short password, 8bits for example. Organizations using RFID tags are therefore concernedthat unauthorized people may (easily) be able to deactivate them evenbefore point of sale. Second, consumers are afraid that the kill commandmay not permanently “destroy” a tag. The entity who made the tag mayalso have means to reactivate it.

SUMMARY OF THE INVENTION

An aspect of the present invention, is to provide transponderinformation exchange privacy and control by providing tag structuresthat make it possible for a user to mechanically alter the tag in such away so as to inhibit the ability of a base station or reader tointerrogate the RFID tag or transponder by wireless means for those tagsthat are readily accessible by the holder of the tagged item.

It is also the aim of this invention to provide a system and method forthe permanent deactivation or disabling of wireless RFID tags unlesselectromechanical means are undertaken to reactivate. Such reactivationwould require deliberate actions on the part of the owner of the RFIDtag to permit the reactivation to take place and could not be undertakenwithout the owners knowledge unless the item were either stolen ordeliberately left unattended. It is further the aim of this invention toprovide a system and method for the visual confirmation that a tag hasbeen deactivated.

Another aspect of the present invention, is to enable a holder of a cardto protect his/her privacy by deactivating the RFID tag at will, whilealso making it possible for an establishment to interrogate the tag atthe holder's discretion by means of mechanical probing.

In order to utilize the methods of disabling to be described we alsorequire a method for manufacturing a wireless RFID tag where thesedisabling techniques to be described can be utilized. The manufacturingmethod consists in the assembly of a memory chip with an externallyaccessible antenna connected to the chip. The chip and antenna aremounted on some mounting means such as a non-electrically conductingsubstrate. The antenna is coupled to the memory chip by way of anelectrical conductor passing through an exterior portion of thesubstrate and at least a portion the externally mounted antenna and theantenna connection in the form of an electrical conductor can bemechanically removed when it is desired to disable interrogation of saidRFID tag.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features, and advantages of the presentinvention will become more apparent from the following detaileddescription when taken in conjunction with the accompanying drawings, inwhich:

FIG. 1 illustrates an example of a system of the invention;

FIG. 2 shows a flow diagram illustrating a disabling function;

FIG. 3 is an example of an RFID tag, whose antenna is constructed of ascratch-off conducting material;

FIG. 4 shows an RFID tag in which the antenna may be disconnected bymechanical means;

FIG. 5 shows an RFID tag in which the antenna may be removed bymechanical means.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides methods, systems and apparatus to protectwireless transponders, such as RFID tags that may be carried on aperson, from an unauthorized interrogation. Such tags have means forreceiving and storing electronic information, commonly in binary formusing memories and/or electronic circuits, typically, but notexclusively such as chips containing ‘bits’ to store the information.The invention is designed to provide privacy of this type of electronicinformation and yet permit the information to be queried later throughmechanical or ohmic contact at the users discretion. At the same timethe tags can be protected from receiving unauthorized or unwantedinformation. The invention provides means that permit a user, generallythe owner, to decide when reception/interrogation of this personalinformation is desirable by simple mechanical means. The disabling ofthe tag to prevent interrogation of the RFID consists in physicallydamaging at least a portion of an interrogation circuit in said RFID tag

FIG. 1, illustrates a system of the invention 100. A person orcardholder 110 carries at least one tagged item 115 which has at leastone wireless or RFID tag 120 attached to the item 115, the card beinginterrogated by an RFID reader 150 which may be located at apoint-of-sale, POS, terminal, the reading transmitted to a computingnetwork. The RFID tag has an antenna 125 connected to a chip on the tagwhich provides a means for communication to the chip. The card may beread through the use of an electromagnetic, EM, signal 160 that providesmeans for communication between the tag 120 and a reader 150.Information received by the reader 150 may be transferred to a computingsystem 170 where it is processed and stored in a database. The system170 may in turn be connected to a network 180 which makes possible theexchange of information with other computing systems. In order toprotect the privacy of the person 110, the tag 120 is constructed with abuilt in means for separating the antenna from the chip. Thus, the usermay mechanically and electrically disconnect the antenna from the chip.

FIG. 2 shows a flow diagram 200 illustrating the disable function. Inorder to be able to assure a consumer that a tag has been deactivated,we provide a method, FIG. 2, wherein there is confirmation of thedeactivation of an RFID tag by physical inspection or electronicconfirmation. Tags are deactivated by the physical destruction of thetag antenna. This is accomplished by means that are familiar toconsumers. Alternatively, tags can be destroyed by destruction of thewiring that is attached to the antenna for those case where the wiringis accessible to the customer.

In the normal state of use for a tag, the tag is functioning and may beconfirmed to be functioning by means of a test 205. The test may consistof placing the tag within the field of an RFID reader, and then usingthe RFID reader to read information held in the memory of the chip onthe RFID tag. If continued functioning is desired 210, no more is done.If the functioning is not desired 210, e.g. the user wishes that the tagmay not be read by wireless means, the antenna is disabled 215. Thedisabling of the antenna is accomplished by mechanical means asdescribed in the figures below. Additionally, the disabling of theantenna function may be confirmed by visual inspection. After the tag isdisabled, the disabling may be confirmed by means of a test However,visual inspection is the preferred method to determine the tag has beendisabled.

Alternatively, if the object is simply to have the tag disabled, thereis no need to first test to see if the tag is enabled. Rather, themechanical disconnection of the antenna connection to the chip or themechanical destruction of the antenna itself is adequate to assure thatwireless radio signals will not be received and will not be conveyed tothe chip. This will disable the tag. The disconnection may be confirmedby visual inspection.

FIG. 3 is an example of an RFID tag that may be disabled by a mechanicalmeans 300. In this embodiment, the antenna is constructed of conducting“scratch-off material”. Such material is familiar to consumers in itsuse to obscure printed material on lottery tickets. Behm et. al.describe the use of such material to construct scratch-off circuits touse in lottery ticket applications, U.S. Pat. No. 5,599,046, anddocument verification, U.S. Pat. No. 5,997,044, herein incorporated byreference. Ask, France,(http://www.ask.fr/uk/technology/ask_technology.html) is a company thatmanufactures printed conducting circuits

In our system, the antenna 310 of the RFID tag 305 is manufactured upona substrate 350 using the scratch off material. The substrate 350 ormounting means may be a plastic material such as polyimide or polyester.The chip 320, also called a memory chip, is mounted on the substrate andis connected to the antenna 310 by an electrical conductor or conductors345. The RFID tag is manufactured in such a way that some or all of theantenna or its connecting wiring is exposed. The electrical conductor orconductors 345 pass through a window 340, e.g. an exterior portion ofthe substrate or mounting means. For instance, an open window 340 in acovering substrate may be built into the tag at or in the region of theconnection of the antenna 310 to the chip 320. Such tags are placed onthe article or on its packaging in such a way that the antenna or theantenna chip connection may be scratched-off using a coin, a fingernail,or other such object. Thus, the consumer or a check-out attendant in aretail establishment, may perform the scratch-off operation to disableinterrogation of the tag. The tag is open for visual observation for theconfirmation of the disabling of the tag.

FIG. 4 shows a second embodiment 400. Perforations 440 such as thoseused to enable the separation of postage stamps from each other aremanufactured into the antenna and its substrate in such a manner that aseparation along a line of perforations, separates the antenna 410 fromthe chip 420, or a sufficient portion of the antenna from itself so asto disable the RFID tag 405. A single or double line of perforations maybe designed into the structure. A pull tab 450 may be added tofacilitate the separation. In this embodiment a double line ofperforations is employed. Thus, the consumer or a check-out attendant ina retail establishment, may perform the separation operation to disablethe tag. The tag is open for visual observation for the confirmation ofthe disabling of the tag. There may also be an auxiliary specializedreader in the retail establishment to give additional confirmation thatthe tag has been destroyed or permanently disabled. Here, the customercan place the item with the tag within the reading range of the specialreader to further ascertain that the tag can no longer be read. Thisreader could simply give a signal such as a continuous blinking light orthe like to indicate that the tag which is within the proper range ofthe special reader is not sending back a signal, i.e. is not being read.

FIG. 5 shows a third embodiment 500. The antenna 510 or portion of theantenna is sandwiched between two layers of packaging material. Thesandwich is manufactured in such a manner that the adhesion of theantenna to the upper layer of the packaging material is greater than itsadhesion to the lower layer which in turn is affixed to the purchaseditem. This produces a peel-off layer 540 affixed by an adhesive materialor layer to the antenna The antenna is removed or destroyed, e.g.delaminated, by pulling the upper layer of material from the tag 505,removing the antenna with it. A pull tab 550 is connected to the upperlayer of packaging is used to facilitate the delamination process. Thetag may be designed in such a way that only a portion of the antenna isremoved, the portion that is above the peel-off line 545. This leaves apair of short antenna lines, or stubs, 550 attached to the chip 520.

Another method for disabling the tag is one where the antenna is formedon a decal with the ends of the antenna in electrical contact with theconnecting stubs. Removal of the decal removes the antenna therebydisabling the chip from receiving any wireless radio frequencycommunication.

Under normal circumstances, the above mentioned methods of removing allor a portion of the antenna would disable the functioning of the antennaand thus the functioning of the RFID tag or transponder in such a waythat interrogation of the tag by wireless means is no longer feasible.However, the remaining short antenna stubs 550 may be electricallycontacted by mechanical probes (the probes electrically connected to oneanother) allowing the reading of the tag through an ohmic contactdirectly to the stubs. These probes may have sharp or sharpened ends inorder to pierce any thin protective layer overlaying the portion of theantenna or stubs still remaining after previous disablement, i.e.resulting from tearing off or destroying the major portion of theantenna as previously described. Thus, even if a tag is disabled from awireless point-of-view, a consumer may allow the tag to be read, forexample, by a retail establishment when an item that the tag is attachedto is returned for a refund or credit. Again, the successful disablingof the tag may be confirmed by visual inspection or through use of theauxiliary reader described above.

It is noted that the foregoing has outlined some of the more pertinentobjects and embodiments of the present invention. This invention may beused for many applications. Thus, although the description is made forparticular arrangements and methods, the intent and concept of theinvention is suitable and applicable to other arrangements andapplications. It will be clear to those skilled in the art thatmodifications to the disclosed embodiments can be effected withoutdeparting from the spirit and scope of the invention. The describedembodiments ought to be construed to be merely illustrative of some ofthe more prominent features and applications of the invention. Otherbeneficial results can be realized by applying the disclosed inventionin a different manner or modifying the invention in ways known to thosefamiliar with the art.

1. A method for manufacturing a wireless RFID tag, said methodcomprising: providing a memory chip, an antenna, and a mounting meansfor mounting the memory chip and said antenna; and coupling said memorychip to said antenna with an electrical conductor passing through anexterior portion of said mounting means, at least a portion of saidelectrical conductor being removable when it is desired to disableinterrogation of said RFID tag.
 2. A method as recited in claim 1,further comprising removing said at least a portion of said electricalconductor to disable interrogation of said RFID tag.
 3. A method asrecited in claim 2, further comprising reconnecting said at least aportion of said electrical conductor to enable interrogation of saidRFID tag.
 4. A method as recited in claim 1, further comprising:removing said at least a portion of said electrical conductor to disableinterrogation of said RFID tag, such as to leave electrical stubs havingan electrical connection to the memory chip.
 5. A method as recited inclaim 4, further comprising connecting an external antenna to said stubsto re-enable interrogation of said RFID tag.
 6. A method as recited inclaim 5, wherein said step of connecting comprises adhering a decalhaving an electrical circuit making contact with at least one of saidstubs to complete an antenna circuit.
 7. A method as recited in claim 6,wherein said decal comprises said external antenna.